The term "attractant" is used in its widest sense and includes trail-following compounds such as the trail pheromones. The invention is especially concerned with preparing and providing an attractant for ants such as the Pharaoh's ant and related species.
The use of substances to lure insects into a situation in which they can be killed or rendered harmless is known. One method of doing this is to lure the insects into a particular location and then cause contact with a pesticide, insect hormone or insect pathogen and the insect to be controlled. In such a case there is no need to disperse the insecticide widely and indiscriminately over large areas, but instead the combination of pesticide and attractant can be placed either as a mixture or as closely spaced quantities, in the neighborhood of those places which have to be protected against the harmful influence of the insects.
A further method is to use the attractant in combination with a trap; the insects ay be killed in this trap or may stick fast to a glue on the walls of the trap. These and other methods for using attractants for controlling insects are known and can be used in accordance with the present invention.
Another important application of attractants is to signal the presence, distribution and spread of the insect. Its presence thus can be detected in good time to take the necessary steps for control and it will not be necessary to use a pesticide outside the period of presence of the insects. Moreover, through use of the attractant a much more definite picture of the extent and intensity of an infestation can be obtained. Thus plans for containment are more feasible and control efforts can be more precisely directed.
Ants, such as the Pharaoh's ant, are in many places a great danger for public health and are often very hard to control. Especially in buildings with central heating, in bakeries and laundries, but also in private houses they form a great problem. The Pharaoh's ant has been shown to be a major carrier of human pathogenic micro-organisms in many hospitals (Susan H. Beatson, The Lancet. Feb. 19, 1972, p. 425: "Pharaoh's ants as pathogen vectors in hospital").
In such places, where the use of toxic substances has to be avoided as much as possible, attractants can be of great importance.